Crown ether-induced supramolecular passivation and two-dimensional crystal interlayer formation in perovskite photovoltaics

It is challenging to realize high efficiency and stability in perovskite photovoltaics simultaneously. Here, we show supramolecular chemistry using macrocyclic crown ether to prepare high-performance metal-halide perovskite films. Multiple cooperative supramolecular interactions between perovskites and crown ether are built, and superior defect passivation is achieved. A thin crystalline capping layer on top of perovskites is constructed to synergistically passivate the perovskite surface defects and protect the underlying films from environmental damage. The capping layer is confirmed to be a unique two-dimensional (2D) crystal with a highly ordered, high-crystallinity lamellae structure and face-sharing lead-halide octahedral organization, providing surface protection on the perovskite matrix. Lead-halide perovskite solar cells (PSCs) with supramolecular passivation and a 2D crystal interlayer demonstrated remarkable photovoltaic efficiency and stability improvements, offering a 21.5% efficiency and improved environmental stabilities under moisture, ultraviolet (UV) irradiation, and thermal stress. Our work provides a strategy to achieve efficient and stable lead-halide perovskite-based devices by crown ether-induced supramolecular passivation and 2D crystal interlayer protection.